Circuit-catching device and electrical system for use in conjunction with the same.



No. 843,270. PATENTED IEB. 5, 1907.

` A. H. GRAVES. CIRCUIT CATGHING DEVICE AND ELECTRICAL SYSTEM IOR USE IN CONJUNGTION WITH THE SAME.

APPLICATION FILED MAY 8. 1903.

TH: Nakms PETERS co., wAsNlNGraN, D. r:

UNITED VEATES PATIENCE IEFICE,

ALBERT H. GRAVES, OF CHICAGO, ILLINOIS.

ClRCUIT-CATCHING DEVICE AND ELECTRICAL SYSTEM FOR USE IN CONIUNCTION WITH THE SAME.

Specification of Letters Patent.

Patented Feb. 5, 1907.

Application tiled. May 8, 1903. Serial No. 156.1 '78.

To (all 'LU/mm, t 'nm/J concern:

Be it known that I, ALBERT H. Gnixvns, a resident of Chicago, in the county of Cool; and State of Illinois, have invented certain new and useful Improvements in Circuitg Catching Devices and Electrical Systems 'for Use in Conjunction with tite Same, of whicl'i the Vfollowing is a specification.

Tl". is invention relates to improvements in circuit-catcling devices and electrical systems for use in conjunction with the same, and it i3 as for its salient object to provide a simple electrically-operated device by ieans oi' which a normally open circuit may be made to close itself and be retained in closed position at the will of tile operator, the invention being particularly applicable to tllose conditions in which it is desired to close a circuit at a point distant from teoperatingstationfas, for example, in telep," one work. Subordinate objects are to provide a system of circuit connections in which tite circuitclosing instrument plays an important part and enables the central-exchange operator of a telephone system to secure a ground connection for a line-wire at a point remote `from t-le central station at will, to provide in a system of tite character last referred to cooperating instrumentalities wl ich permit one or more subscribers along tIe line bctween tite circuit-catciiing device and ccntral to ground tite line without tl" ereby torming a ground connection through tle circuiteatclLing device, to provide an arrangement and connections wi ereby tile ground connection through tire circuit-catciiing device is automatically opened and remains open except when intentionally closed and so retained by tiie operator at central, and, in general, to provide an improved system oi ti e cl araeter referred to.

To tle above ends tiie invention consists in the matters iereinaiiter described, and more particularly pointed out in tlc appended claims, and the invention will be readily understood from the drawings forming a part of tie description, and inwi ich tsc main Figure 1 illustrates one of ti e improved circuit-catcliing instruments in side elevation and diagrammatically a system ol' circuit connections, showing tl'e instrument applied as a part of a party-line telephone system.

Fig. 2 illustrates a modification in Which a single spool ltaving a two-part winding performs tre functions of the two-spool magnet illustrated at A, Fig. l.

Describing7 iirst, the construction of the circuit-catching instrument, (designated as a wiole A,) 2 designates a suitable lieel-piece constructed in tlc present instance to serve also as a trame member and Alier this purpose provided at each end with uprights, as 3 and e, rigid with the heel-piece 2. Upon the lool-piece are mounted two magnet-spools 5 and 6, tlc former being relatively lower wound and tiie latter wound to a liigler resistance for purposes lereinalter explained.

7 designates an armature pivotally mounted upon tlie upriglit 3, as indicated at 8, and arranged to extend in proximity to tle polepieccs of tl3e two magnet-spools, so as to be acted upon by eitier or both el tle latter. Upon tile 'lree end of tle armature is mounted a spring 9, wit ich rests in engagement at its outer end with an adjusting-screw l0, mounted witlin the upright 4 and insulated tlerei'rom, as indicated at l1. Tite spring 9 determines tie normal position of the armature relatively to the pole-pieces of the magnet. I

12 designates a cont'act-point or screw adjustably .mounted in the upright 4, and 13 designates a spring contact-strip mounted upon the armature 7 and adapted to contact with said screw 12 when the armature is drawn into closed position. The upright 4L is insulated `from the remainder of the frame, as indicated at 14, and with said upright is connected a conductor 15, which extends to and through the magnet-spool 5 and thence to ground, as indicated at I6.

17 designates diagranunatically a condenser which may be of any usual iorm, one side of said condenser being connected with a main-line wire I8 through a conductor 1Q, whilel from the opposite side o'lt the condenser leads a conductor 20, which extends to and through the windings of the magnet-spool 6 and thence to ground. A continuation 1S of the main line 1S beyond the branch 19 leads to and is connected with the armaturelever 7, as indicated at 21.

Describing now the circuit connections, B designates as a whole a central-station appa- ICO ratus, and C, D, and E a plurality of subscribers stations, only so much ot each of these stations being shown as is necessary to understand the application of the invention. At the central station is provided a battery 22, one side of which is grounded, as indicated at 23, while the other side is connected with the main line 18. A signal device-as, for example, a drop 24 is interposed in said main line, and between the drop and the eX- tension of the line which leads to the subscribers stations is interposed a key 25, nor- Inally closing the circuit through the drop at a back contact 26. The key 25 is arranged to cooperate with a normally open contact 27 in such manner as to produce a momentary ground, and to this end the contact 27 is a yielding contact the body of which norm ally rests in engagement with a back contact 28, connected to ground through a conductor 29. In operating the circuit-catcher the drop 24, which is wound to a comparatively high resistance, is cut out or short-circuited, and to this end a second contact member 30 is arranged in the path 'of the key 25 and connected with the main wire 18 at a point between the drop and battery, as indicated at 30. The contact member 30 is so arranged that the engagement of the key therewith will occur after the momentary ground through contacts 27 and 28 has been made. C, D, and E represent the instruments which are operated over the main line 18 after the latter has been closed to ground by means of the circuit-catcher. rt'

The pai Licular function performed by the instruments C, D, and E is immaterial to the broader scope of the invention but in the present instance said instruments represent selecting devices which when operated place certain parts in definite position from which they are restored by means of clearing-magnets 31. These clearing-magnets are operated through the main line 18, and it is the function or' the circuit-catching device to close a circuit for this purpose. Each selector instrument comprises in addition to the clearing-magnet a second magnet 32, an armature 33, and a contact-lever 34, and a latch 35, mounted upon the armature 31 or' the clearing-magnet. By means ofcircuit connections (not shown) the magnet 32 operates to place the lower end of the contact-lever 34 in latched engagement with the latch 35. When the clearing-magnet is energized, its armature is drawn down, thus releasing the contact-lever, which thereupon returns to its normal position under the action of a spring. T he main line 18 is employed in operating the signaling device or drop 24 from each subscribers station. To thisend a branch conductor 36 is connected with said main line at each subscribers station and extends thence to the hook-lever 37.

38 designates a spring-contact mounted above the hooked lever and pro vided with a contact-point 39, which is engaged by the hook-lever as the latter rises, but normally stands open.

40 designates a contact device with which the yielding contact 38 normally rests in engagement at a point intermediate its length, as indicated at 4l, and which contact 41 is open when the hook-lever raises the cont-act 38. The contact 40 is connected to ground, as at 42, by a conductor 43. It will be obvious that the foregoing arrangement produces a momentary or flush grounreach time the hook-lever rises.

The operation of the apparatus may be briefly described as follows: Tracing the main-line circuit and the branches thereof from ground at central through the battery 22, it will be seen that the circuit is open at the remote end of the line at the condenser 17 and that all of the several branches thereof at the subscribers stations are likewise open. In this condition any subscriber can operate the signal or drop 24 by removing his receiver from the hook-lever, thus closing a circuit from ground at said subscribers station to ground at central through the battery. The placing of the line to ground at any subscribers station will obviously discharge the condenser, and thus cause the high-wound coll 6 of the circuitcatcher to operate the armature; but inasmuch as the subscribers ground is interposed between the battery and the circuit-catcher the latter will simply make a single kick and immediately return to its normal open position. The interposition of the high resistance 24 insures that upon the operation of the circuit-catcher by the momentary grounding at a subscribers station the holding-circuit through the low-wound coil of the instrument will not be effective in making a permanent ground, although the holding-circuit is for an instant closed. The several subscribers may therefore signal in to central for connections with impunity and without thereby establishing a ground connection through thel circuit-catcher. As sunn'ng, however, that one or more of the selector instruments have been operated and it is desired to clear the selector or selectors, the operator at central accomplishes this by depressing the key 25. The iirst part of the downward movement of the key opens the main line through the drop and immediately thereafter closes it to ground through the contacts 27 and 28. This instantly discharges the condenser; but since at this moment the circuit through the battery 22 is open the circuit-catcher will instantly return to its open position. The further depression of the key 25 closes the main line through the contact 30, which IOS contact, it will be noted, is between the resistance 24 and the battery, so that the condenser becomes instantly charged under the full voltage of the battery, and in se becoming charged the circuit-catcher is closed by the flow of current Vfrom ground to the condenser through the high-resistance coil thereof. Since the battery is now on the line, it follows that as soon as the holdingcircuit is established by the closing` of the armature of the circuit-catcher the latter will remain in its closed position as long as the key 25 is held depressed, thereby operating the clearing-magnets. Obviously as soon as the pressure of the liey is released and the main-line circuit opened between the contact 30 and the key the circuitcatcher will return to its open position, thereby opening the holding-circuit from the low-wound coil thereof and restoring the line to its normal condition.

Vhile in the preferred embodiment thus far described the circuit-catching instrument is shown as comprising two separare coils or magnets, yet it will be seen on tracing the circuits 'that a single magnet may be made to accomplish exactly the same functions as do the two, the latter construction being adopted simply as a convenience in manufacture. Accordingly in F ig. 2 I have shown a modifica'iion in which a single magnet is arranged to perform the functions of both those illustrazed in Fig. l. The construction and arrangeinen't are identical, with 4the exception that that part of the holding-circuit consisting of the conductor l5', leading from the contact-screw or the support 4, upon which it is mounted, extends to and through a part of the windings of the single magnet 6.

It will be obvious from the foregoing that the details of construction and arrangement are not essential and that they may be modified without departing 'from the spirit of the invernion. It will be further obvious that, as hereinbefore intimated, the invernion is not limited to the particular application herein shown, but, on the contrary, it may be found useful for a variety of purposes, and especially in various relations in telephone systems. However, it will be seen that the invention possesses special iniliry in the par- -iicular system described herein., and accordingly it is claimed both broadly or independently of the sysiem and in combination therewith.

l claim as my invention-- 1. A circuit-catching mechanism, co-mprising an electric circuit and source of current-supply, a condenser ini'erposed in said circuit, a magnet, having an automaticallyreturning armature, and arranged in circuit with the condenser, said magnet being provided with a main winding of high resistance,

and a retaining-winding of a resistance subl circuit catcher magnet,

stantially as low as is consistent with ret aining the armature reliably in closed position, and a shunt leading around said condenser, including said retaining-winding, and controlled by said armature.

2. A circuit-catching mechanism, comprising an electric circuit and source of current-supply, a condenser interposed in said circuit, a magi'iet, having an automaticallyreturning armature, and arranged in circuit with the condenser, said magnet comprising two spools, of which one is provided with a main winding of high resistance and the other with a retaining-winding of aresistance substantially as low as is consistent with holding the armature reliably in closed position after closing, and a shunt leading around said condenser', including said retainingwinding and controlled by said armature, said armature being arranged to extend in operative relation to the cores of both inembers of said magnet.

3. A circuit-catching mechanism, comprising an electric circuit and source of current-supply, a condenser inl erposed therein, a retaining-magnet in circuit with the condenser and having an autematically-returning armature, said magnet being provided with two coils, and self-maintaining circuit connections controlled by said armature and comprising a normally open shunt leading from the main line around the condenser and through a part only of the coils of the retaining-magnet and normally open at a contact controlled by said armature.

4. In a telephone system, the combination of an electric circuit, a source of current-supply connected with said circuit, a condenser and a circuit-catcher magnet interposed in said circuit, a resistance and key-controlled circuit connections whereby said resistance may be interposed between the source of current-supply and the condenser and cut out of the circuit at will, an armature operable by said circuit-catcher magnet, and self-maintaining circuit connections controlled by said armature and including a branch conducto r leading around the condenser, as and for the purpose set forth.

5. In a telephone system, the combination of a line conductor extending from an operators station to a remote station and grounding connections at each station, a battery interposed in said line, a signaling device interposed in the vline at the operators station, a key arranged to open the circuit as to the said signaling device and as to the battery, and arranged to close the circuit to ground at the operators station, a condenser interposed in the circuit, and a circuit-catcher magnet likewise interposed in the circuit in series with the condenser and at a point beyond said remote station, an armature controlled by said self maintaining TOO ITO

shunt-'circuit connections controlled by said f circuit closed and means for grounding said armature and including a branch conductor line conductor at said remote station. leadlng from the main line around the c0n- ALBERT H GRAVES denser and to ground, said shunt-ercut conneetons forming When closed a circuit of subfitnessesz stanlally as 10W reslsance as 1s conslstent FREDERICK C. GOODWIN, Wrbhgmalntalnlng the magnet energlzed and A. M. CRONA. 

